Community-acquired infections are an important cause of admission of children to hospital. We have made a 2-year prospective study of 1,599 children admitted with infection to the Royal Liverpool Children's Hospital in order to determine the pattern of infections, their seasonal distribution and the role of the laboratory in isolating causative agents. Respiratory infections (32% cases) and gastroenteritis (28% cases) were the principal causes of admission. Of all admissions, 64% were children aged less than 1 year. Appropriate specimens were obtained and/or investigations made of 48% cases. Overall, a causative agent was determined in 21% cases. Individual pathogens showed marked seasonality. Respiratory syncytial virus, rotavirus and Shigella species were found more often in the winter months, while Salmonella species and adenovirus infections were most common in the summer. The results provide local data that is relevant to both public health and hospital planning. They also emphasise the need for continuing surveillance of community-acquired infections.